The letters were signed by the commandant of the Philadelphia Navy Yard.
"Look at that," said Slim, pushing his letter at Lieutenant Mackinson, utterly forgetful of the fact that the other man was his superior officer. "Ain't—isn't that fine, though? For the commandant to mention it that way, I mean."
"Yes," admitted Lieutenant Mackinson, "but he wouldn't have mentioned it that way if you hadn't deserved it."
"I'm not going to lose that letter," announced Jerry.
"Nor I," added Joe, "although we only did what any other fellows would have done under the same circumstances."
"Well," said Lieutenant Mackinson, "it showed that you were to be depended upon in an emergency, and emergencies are likely to crop up at any time in our work, so let's get down to business."
He immediately began explaining the apparatus of the wireless room—how messages were sent and received; the power of the batteries and their auxiliaries; the switch-board regulating voltage; the automatic recording apparatus—in fact, every detail connected with the intricate mechanism of an up-to-date wireless.
"There was a time," explained Lieutenant Mackinson, "when the sending of a message almost deafened the sender. It was like being in the midst of a machine-gun assault. But recent improvements have eliminated that. You may see for yourselves."
And the lieutenant tapped off the Everett's own signal call with little more sound than is made by the sending of a message with the ordinary telegraph instrument.
"We have a sending and receiving radius of from five hundred to eight hundred miles," Lieutenant Mackinson continued. "Of course, it doesn't compare with the great wireless station at Radio, Virginia, one of the largest in the world, where one tower is six hundred feet high and the other four hundred and fifty feet in height, and each charged with two hundred thousand volts, giving a radius of three thousand miles; but it is sufficiently powerful for practically every purpose required at sea."